A 13-ounce box of cereal sells for $3.25. An 18-ounce box of cereal sells for $3.60. Which statement describes the difference in the unit prices of the two boxes of cereal?

A. The 13-ounce box is 5 cents cheaper per ounce.

B. The 13-ounce box is 7 cents cheaper per ounce.

C. The 18-ounce box is 5 cents cheaper per ounce.

D. The 18-ounce box is 7 cents cheaper per ounce.